It is known to capture real-time 2-D images by means of a camera carried by an unmanned aerial vehicle (UAV) and to transmit those images to a remote location for display on a display device. A human operator may then view the images at the remote location. Such a system can be used in connection with loitering airborne munitions to enable an operator to detect, recognise and identify a target. Current systems use 2-D images relayed to the operator for target re-acquisition decision making where the perception of perspective and depth is limited. The present invention is concerned with a system and method that enables the afore-described real-time display of a 2-D image of a region to be improved by means of displaying a stereographic image.
A known method of producing a stereographic image is to capture simultaneously images with two spaced-apart cameras and using the image captured by one camera as the left image of a stereographic image and the image captured by the other camera image as the right image of the stereographic view. Providing two cameras on board the aircraft to provide a stereographic display for the operator might improve the usefulness of the images displayed to the operator, in comparison to a conventional 2-D system, but would require an extra camera and would only provide a relatively flat stereographic image as a result of the likely small separation of the two cameras on the UAV (in practice very unlikely to be more than 4,000 mm) relative to the separation of the UAV and the intended target (typically of the order of a few kilometers or greater)
WO03/032649 relates to an aerial reconnaissance camera system. A single camera in a moving aircraft rotates fore and aft to capture images of the surrounding terrain in different directions so that, as the aircraft flies past, any given location in the terrain of interest is imaged from two different perspectives. The captured images are stored on a suitable recording medium for subsequent production of stereoscopic images of the terrain. The apparatus of WO03/032649 is thus able to map an area of terrain for subsequent analysis, including production of stereographic images, but can not assist in providing real-time stereographic information concerning a particular region in the terrain being mapped.
The present invention seeks to provide an improved method and apparatus for displaying stereographic images of a region.